This invention relates to a process for producing deep-drawable sheets and strip from a zinc-copper-titanium alloy by means of continuous casting machine with moving flexible belts and with continuous finish-rolling without change of direction, from a zinc-copper-titanium rolling alloy which is creep-resistant according to DIN 17 770 and foldable according to DIN 1 623, consisting of 1.5 to 5.5% copper, 0.05 to 0.25% titanium and, if desired, 0.005 to 0.05% aluminum, balance zinc. Deep-drawing is used to make hollow pieces from sheets in such a manner that the shaped pieces can be reshaped on a commercial scale without incipient cracks and without substantial earing. There are two basic methods to render sheet metal deep-drawable as it is reshaped, namely by the deforming technology and by the alloying technology.
It is known from "Metall"16, 8, 1962, pp. 750/52, that the mechanical and technological properties of a titanium-containing zinc rolling alloy, inclusive of the deep-drawability, can be influenced by the copper content.
From Japanese Pat. Application 14 596/1968, there is known a process for the production of a deep-drawable zinc alloy which contains 0.3 to 3% of one or more of the metals copper, aluminum, nickel, beryllium, manganese, cadmium, as well as 0.03 to 0.16% of one or several of the metals titanium, magnesium, molybdenum, zirconium, tantalum, chromium, and which is treated at a temperature above 250.degree. C, mostly 300.degree. to 400.degree. C, and then submitted to cold rolling, with a deformation of 20 to 60%. The deep-drawability of this alloy amounts to 1.90 to 1.198. There is also known a process (German OS 18 14 657) wherein a zinc alloy containing 0.05 to 2.0% copper and 0.005 to 0.4% titanium is hot-rolled at 230.degree. to 270.degree. C, with a reduction of 85 to 95% in at least one pass to reduce the earing during the drawing of the sheets produced from this alloy.
Attempts to also use these procedures known from the prior art for the production of deep-drawable zinc-copper-titanium rolling alloy which is creep-resistant according to DIN 17 770 and foldable according to DIN 1 623, being composed of 1.5 to 5.5% copper, 0.05 to 0.25% titanium and in some cases 0.005 to 0.05% aluminum, balance zinc, were not successful.